In the United States of legal abortion can be performed only by a licensed physician. Professional control over access to abortion means that the decisions and action of physicians and health institutions as to when, where, and under what circumstances abortion services will be provided are of major significance in determining the availability of these services to abortion seeking women. Evidence from data collected by this investigator, as well as others, indicates that there is wide variation in provision of abortion services and in policies and practices that determine the manner of provision. The objective of this research is to analyze data from three surveys carried out in Maryland- of physicians (obstetrician-gynecologists and general practitioners), of hospitals and free-standing clinics, and of agencies that engage in abortion referral. These surveys focused on the provision of abortion services, and on policies that govern acceptance of women for service, patient management, and referral. The purpose of data analysis will be to account for the variations in patterns of service that have been observed. Four groups of explanatory variables will be considered: (1) estimated need for abortion services; (2) the background and values of individual health care professionals; (3) organizational characteristics of hospitals and health agencies; (4) the location of professionals and institutions in communities, and in professional and organizational networks. The role of the health care system has been largely neglected in research on the control of fertility. The proposed analysis will result in a detailed account of this role as it affects abortion services; and may contribute to a more general understanding of professional and constraints on the delivery of fertility related health services.